firewire: core: use guard macro to maintain the list of address handler for transaction

The core function maintains address handlers by list. It is protected by
spinlock to insert and remove entry to the list.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-8-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

drivers/firewire/core-transaction.c

@@ -596,7 +596,7 @@ int fw_core_add_address_handler(struct fw_address_handler *handler,
 	    handler->length == 0)
 		return -EINVAL;
 
-	spin_lock(&address_handler_list_lock);
+	guard(spinlock)(&address_handler_list_lock);
 
 	handler->offset = region->start;
 	while (handler->offset + handler->length <= region->end) {
@@ -615,8 +615,6 @@ int fw_core_add_address_handler(struct fw_address_handler *handler,
 		}
 	}
 
-	spin_unlock(&address_handler_list_lock);
-
 	return ret;
 }
 EXPORT_SYMBOL(fw_core_add_address_handler);
@@ -632,9 +630,9 @@ EXPORT_SYMBOL(fw_core_add_address_handler);
  */
 void fw_core_remove_address_handler(struct fw_address_handler *handler)
 {
-	spin_lock(&address_handler_list_lock);
+	scoped_guard(spinlock, &address_handler_list_lock)
 		list_del_rcu(&handler->link);
-	spin_unlock(&address_handler_list_lock);
+
 	synchronize_rcu();
 }
 EXPORT_SYMBOL(fw_core_remove_address_handler);